A NASA-funded Applied Sciences Program to develop an operational prototype for a global, real-time, data-driven predictive system needed to assess biologically harmful radiation exposure levels for aviation

Current Dose Rate:The NAIRAS model predicts atmospheric radiation exposure from galactic cosmic rays (GCR) and solar energetic particle (SEP) events. GCR particles propagation from local interstellar space to Earth is modeled using an extensionhe Badhwar and O'Neill model, where the solar modulation has been parameterized using high-latitude real-time neutron monitor measurements at Oulu, Tomnicky, and Moscow. During radiation storms, the SEP spectrum is derived using ion flux measurements taken from the NOAA/GOES and NASA/ACE satellites. Transport of the cosmic ray particles - GCR and SEP - through the magnetosphere is estimated using the CISM-Dartmouth particle trajectory geomagnetic cutoff rigidity code,driven by real-time solar wind parameters and interplanetary magnetic field data measured by the NASA/ACE satellite. Cosmic ray transport through the neutral atmosphere is based on analytical solutions of coupled Boltzmann transport equations obtained from NASA Langley Research Center's HZETRN transport code. Global distributions of atmospheric density are derived from the NCEP Global Forecasting System (GFS) meteorological data.

Credit/Acknowledgment: The NAIRAS information is publicly provided by Space Environment Technologies at http://sol.spacenvironment.net/nairas/index.html. This site is hosted in conjunction with the NASA Langley Research Center and the team behind NAIRAS is identified at that site.